From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_ALL,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71562C433EF for ; Fri, 24 Sep 2021 11:18:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0AD6E600D4 for ; Fri, 24 Sep 2021 11:18:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0AD6E600D4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=megous.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=CvBEb8uWrp22AOMteprVIwYGhyKj/X+XrSfLsiXdXu0=; b=Dr6+JgNj4M4bH5 VvoHkiWgRPPhnFSWa1Gmt+mBC2wT9j1aq3jOX7jKkRgEK3TLghSWVkSgG3WWAGuEU0tfkXFqnuOM0 JECuVviF17FLX20x5yQQ/89QbkU3ymq9I3RzwzgsT92L9Zp/afd8EMK2swDQf+DjN5ouNkgW4F0XF 64zup/D8vIC2vx+/RadeLYz7+aaLECj+g01OY2/h00ePtQkHOYtwgcCL6OzxxsLQRVo7wxIlLMEbi naiSaFpvyuri9KyzhjrllECNFLYucoNrZHFzJPKZyZcYOL7pQgjwg4/owGE/KU471gCCYeQkS+UHH yuQFRyNaACX5oiUplHUQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTjBY-00E9Jp-RK; Fri, 24 Sep 2021 11:16:08 +0000 Received: from vps.xff.cz ([195.181.215.36]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTjBS-00E9J8-Vs; Fri, 24 Sep 2021 11:16:07 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1632482157; bh=34Gdmo0642tbeuZPW9xMHWN5BVp3DeIPofJxo02CEC4=; h=From:To:Subject:Date:From; b=jQokJeTan2xkic0EAF1IeKF14DZmV7zjr4hNZFk1T6rBw8XSKtUGEPAlS79EUSQrc OZ9A4xtrYQpuiReKJp2o2NoBOMJIxlTWuZ1DwiCOi4JTQvmdc33rImPQqXDIoasBGf d5R698DmaF140KY0y+FGkxOZTnFZ1ukzvhBJtaKc= From: Ondrej Jirman To: Heiko Stuebner , Wolfram Sang , Krzysztof Kozlowski , Ondrej Jirman , linux-arm-kernel@lists.infradead.org (moderated list:ARM/Rockchip SoC support), linux-rockchip@lists.infradead.org (open list:ARM/Rockchip SoC support), linux-i2c@vger.kernel.org (open list:I2C SUBSYSTEM HOST DRIVERS), linux-kernel@vger.kernel.org (open list) Subject: [RESEND PATCH] i2c: rk3x: Handle a spurious start completion interrupt flag Date: Fri, 24 Sep 2021 13:15:27 +0200 Message-Id: <20210924111528.2924251-1-megous@megous.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210924_041603_379210_DBBF8B75 X-CRM114-Status: GOOD ( 10.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In a typical read transfer, start completion flag is being set after read finishes (notice ipd bit 4 being set): trasnfer poll=0 i2c start rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10 i2c read rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b i2c stop rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 33 This causes I2C transfer being aborted in polled mode from a stop completion handler: trasnfer poll=1 i2c start rk3x-i2c fdd40000.i2c: IRQ: state 1, ipd: 10 i2c read rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 0 rk3x-i2c fdd40000.i2c: IRQ: state 2, ipd: 1b i2c stop rk3x-i2c fdd40000.i2c: IRQ: state 4, ipd: 13 i2c stop rk3x-i2c fdd40000.i2c: unexpected irq in STOP: 0x10 Clearing the START flag after read fixes the issue without any obvious side effects. This issue was dicovered on RK3566 when adding support for powering off the RK817 PMIC. Signed-off-by: Ondrej Jirman --- Re-sending, because originally, maintainers script did not pick up rockchip mailing list, to send this patch to. drivers/i2c/busses/i2c-rk3x.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index 819ab4ee517e..02ddb237f69a 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -423,8 +423,8 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) if (!(ipd & REG_INT_MBRF)) return; - /* ack interrupt */ - i2c_writel(i2c, REG_INT_MBRF, REG_IPD); + /* ack interrupt (read also produces a spurious START flag, clear it too) */ + i2c_writel(i2c, REG_INT_MBRF | REG_INT_START, REG_IPD); /* Can only handle a maximum of 32 bytes at a time */ if (len > 32) -- 2.33.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel